package cn.edu.ctbu.dp001.service;

import cn.edu.ctbu.dp001.constant.REnum;
import cn.edu.ctbu.dp001.dao.StudentRepository;
import cn.edu.ctbu.dp001.entity.Student;
import cn.edu.ctbu.dp001.exception.RException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Example;

import org.springframework.data.domain.*;
import org.springframework.stereotype.Service;
import java.util.List;

@Service
public class StudentService {
    @Autowired
    public StudentRepository studentRepository;

    /**
     * 读所有的学生列表
     * @return List Student
     */
    public List<Student> getAll(){
        return studentRepository.findAll();
    }

    public Page<Student> getAll(Pageable pageable){
        return studentRepository.findAll(pageable);
    }
    public Page<Student> getAll(Example<Student> example, Pageable pageable){
        return studentRepository.findAll(example,pageable);
    }


    /**
     * 按id进行查询
     * @param id 主键，整数
     * @return List Student
     */
    public Student findById(Integer id) {

        return studentRepository.findById(id).get();
    }

    /**
     * 按名字进行查询,like
     * @param
     * @return List Student
     */
    public List<Student> findByName(String name) {

        return studentRepository.findByNameLike(name);
    }

    /**
     * 按名字、密码进行查询
     * @param name
     * @param password
     * @return
     */
    public List<Student> findByNameAndPassword(String name,String password) {
        return studentRepository.findByNameAndPassword(name, password);
    }

    public void insert(Student student) {
        studentRepository.save(student);
    }

//    public void update(Student student) {
//        studentRepository.save(student);
//    }

//    public void delete(Integer id) {
//        studentRepository.deleteById(id);
//    }

    /**
     *
     * 新增学生
     * @param student
     * @return
     */
    public Student add(Student student) {
        return studentRepository.save(student);
    }

    /**
     *
     * 更新学生
     * @param student
     * @return
     */
    public Student update(Student student) {
        return studentRepository.save(student);
    }

    /**
     *
     * 删除学生
     * @param id
     */
    public void delete(Integer id) {
        studentRepository.deleteById(id);
    }

    public void deleteMultiple(List<Integer> ids) {
        for (Integer id : ids) {
            // 先检查 ID 是否存在，避免删除不存在的记录
            if (studentRepository.existsById(id)) {
                System.out.println("准备删除学生 ID: " + id);
                studentRepository.deleteById(id); // 删除操作
            } else {
                System.out.println("ID " + id + " 不存在，跳过删除");
            }
        }
    }

    public Student validateUsernameAndPassword(String sno, String password) throws Exception{
        List<Student> students=studentRepository.findBySno(sno);
        if(students.size()>0){
            //可能对password加密，但我们暂时不做处理
            Student student=students.get(0);
            if(student.getPassword().equals(password)){
                //成功
                return student;
            }else{
                throw new RException(REnum.LOGIN_ERR);
            }
        }
        else{
            throw new RException(REnum.LOGIN_ERR);
        }
    }
}